1. Field of the Invention
The subject invention relates to the use of alkali metal ammonium carboxylates as catalysts in the preparation of rigid and flexible foams characterized by isocyanurate and/or urethane linkages. Alkali metal ammonium carboxylates are the reaction products of a tertiary amine and an alkali metal acid salt of a polycarboxylic acid.
2. Description of the Prior Art
Rigid and flexible foams characterized by isocyanurate and/or urethane linkages are known in the art. The prior art discloses methods for preparing foams by reacting an organic polyisocyanate with a polyol in the presence of a catalyst and a blowing agent.
U.S. Pat. No. 4,136,240 discloses metallic quaternary ammonium carboxylates, which are the reaction products of a tertiary amine, a monoalkali metal salt of a dicarboxylic acid, and an alkylene oxide. These products are used as catalysts in the preparation of rigid and flexible foams characterized by isocyanurate and/or urethane linkages. The patent, however, does not disclose any utility for alkali metal ammonium carboxylates which are intermediates in the preparation of the reaction products of this patent.